1. Field of the Invention
This invention relates generally to a structure for supporting a payload such as a spacecraft or a satellite in a launch vehicle and, more particularly, to such a structure having facilities for accommodating nominal misalignment between the attachment points of the structure and the supporting points on the launch vehicle.
2. Description of the Prior Art
The advent of a launch vehicle such as the space shuttle with its wide cargo bay permitted the development of larger space vehicles than were accommodatable on conventional, expendable rocket boosters. To maximize the utilization of the available space in the cargo bay, particularly with respect to a cross-sectional area, a new satellite and launching technique were developed as described in U.S. Pat. No. 4,359,201. Here, a spin-stabilized spacecraft of circular cross-section is mounted with its spin axis parallel to the longitudinal axis of the shuttle. The spacecraft is mounted in a carrier depicted as a cradle which, in turn, is secured to the longeron bridges and the keel of the space shuttle. The spacecraft is deployed from the shuttle with linear and angular velocity as though it were rolling up a ramp out of the shuttle bay, and thus is initially spin-stabilized as it moves away from the shuttle.
The spacecraft is constructed of a tubular truss frame which is integrated with a lightweight cradle which, in turn, is attached to the shuttle bay main frames which is comprised of a pair of upper longeron bridges bridging the bulkheads and a lower cargo bay keel bridge.
The tubular truss frame of the spacecraft is relatively stiff and when integrated with the lightweight cradle, stiffens the cradle. One or more of the cradle attach points therefore require shimming to compensate misalignment with the shuttle longerons and keel bridges when the integrated spacecraft and cradle are secured in the shuttle bay. Space limitations require removal of the integrated spacecraft and cradle for each adjustment until all four of the attach points engage the upper longeron bridges.